Two vehicles were involved in a head-on collision in Carmichael on Saturday evening, resulting in serious injuries to six people, officials said.

A female driver and three passengers were headed north on Manzanita Avenue near Jameson Court in a Honda Pilot around 6:30 p.m., California Highway Patrol Officer Chad Hertzell said.

“For some unknown reason, she veered to the left and crossed over into oncoming traffic,” Hertzell said, crashing head-on with a Subaru Legacy carrying a female driver and one passenger.

Five people were driven to hospitals and one was taken by helicopter, all with major injuries, Hertzell said.

Hertzell said the investigation had not determined if alcohol or drugs were involved.